Abstract: An apparatus is provided for disabling valve cusps within a vein. A flexible guide tube of a diameter substantially smaller than that of a vein has at least one retractable wire hook for ensnaring a valve cusp within the vein. The wire hook may be continuously moved from a retracted position against the tube end to an extended position toward a vein wall. Valve cusps are trapped by a narrow gap at the end of the hook, and are disabled by pulling the sharp point of the hook through them.